An overcoat layer is commonly placed on top of magnetic recording media to protect the magnetic media layers under the overcoat from corrosion. The overcoat can serve to reduce friction and wear caused by intermittent head-disc contact. One well-known overcoat material is diamond-like carbon (DLC) material. A typical thickness of the DLC overcoat layer ranges from 2.5 nm to 4.0 nm.
On top of this overcoat layer, there is usually a thin layer of liquid lubricant that acts as the buffer layer to further reduce corrosion, as well as to serve as a lubricating layer for the air bearing slider to glide over. A typical lubricant is a perfluoropolyether (PFPE), e.g., Fomblin® Z and Y lubricants from Solvey Solexis Inc. A typical thickness of the lubricant layer is between 1 and 2 nm.
As the areal density is increased in hard disk drive industry, the head-to-media spacing (HMS) must also be reduced. To this end, it is desirable to provide an alternative to the current two protection layers, e.g. lubricant and overcoat.